Anterior cervical plating systems are well known, and there are a number of different such systems on the market. All currently available plating systems use a metal, usually titanium although any suitable surgical material may be used, plate, screws which go through the plate into the vertebra, and a locking mechanism, whereby the screw is locked to the plate. Locking is accomplished by a variety of mechanisms; a CSLP (a smaller central screw expands the head of the bone screw to lock it into the plate), a lock washer or press fit which locks the screw into the plate, or a locking device attached to the plate which is applied to the screw after it has been tightened. These designs include cams, washers, plates and screw-on caps applied to the plate after the screw has been engaged. Initial plate designs were rigid, but this led to the concept of stress shielding, and it was felt that rigid plates prevent loads from being transmitted through bone grafts, which can interfere with fusion and allow for grafts to be reabsorbed.
Although a substantial number of different plate designs have been developed, few of these systems adequately address a difficult surgical problem, revision surgery. Revision surgery is required in a patient who has already had an anterior cervical fusion, and who develops adjacent level disease. With current anterior cervical plating systems it is necessary to remove the previous plate in order to operate on the additional level. If a patient has had multiple levels done, the prior plate must come off of all of the previous levels in order to plate the previously unoperated adjacent level This is difficult surgically, and is associated with increased operative morbidity.
Accordingly, a need exists for an improved anterior cervical plating system with improved interconnectivity such that revision surgery is less intensive and traumatic to the patient.